Conventional cleaning brush products for washing dishes or hard surfaces require liquid cleaner and water to develop a lather of cleaner on the brush head. Conventional cleaning brushes provide a liquid cleaner reservoir built into the handle of the brush. The liquid cleaner, such as soap, is often dispensed by way of gravity through a small hole in the head of the brush. The liquid cleaner can leak out of the head of the brush when the brush is not in use, especially when some form of check valve is not built into the brush. Other conventional cleaning brushes incorporate a small rubber button on the liquid reservoir that acts as a displacement device when pushed into the reservoir. The button, when pressed, occupies space in the reservoir that compresses the liquid cleaner forcing it out of the opening in the brush head. As the soap level in the reservoir is lowered during use, the displacement button becomes ineffective because the air in the reservoir makes the compression ineffective. The increased compressibility of the air requires an increased displacement to eject any cleaner, which the button cannot provide.
Known brushes also require an external use of water and agitation by the user to generate a lather of cleaner foam on the object that is being cleaned. A separate supply of water can be unwieldy or unavailable, as clean water is not always available when cleaning objects during travel, in a car, or outside, as when camping. Moreover, cleaning in tight spaces, such as inside a drinking glass can be difficult with conventional fixed-head cleaning brushes because the head is invariably angled and cannot make flat contact with the bottom of the glass, for example.